When the killing of an unarmed black man in Oakland, California, by a police officer, triggered the community into angry disorder, local police called in reinforcements.

Numerous federal and local enforcement agencies were brought in to infiltrate crowds, subdue demonstrators and assist in mass arrests as a part of actions that lawyers say were unconstitutional and violate the police's own regulations. Ali Winston, a local journalst with The Informant, first published some of the same documents that Al Jazeera obtained in a report published December, 2010.

In the midst of an austerity crisis, local authorities also equipped themselves with a sophisticated weapons arsenal ranging from flash-bang grenades to deadly sound cannons which are now close at hand for future action.

Activists in Oakland say that their experience with the "increasing militarisation of society", by intensifying the funding and riot-preparedness of police, is not a path to establishing peaceful communities - in either the US or the UK.

"b***h a*s n****r"

Early on January 1, 2009, Oscar Grant was shot in the back and killed by a white police officer while being handcuffed and lying down on a subway platform in Oakland. Just before he was killed, Grant watched another officer throw his friend against a wall and use the phrase "b***h a*s n****r" twice.

Bystanders captured the shooting on video and people in the community responded with numerous angry demonstrations in downtown Oakland over almost two years while the officer was on trial for murder.

Just as in London, media reports called the immediate aftermath of Oakland's anger "riots". Police responded with multiple uses of flash-bang grenades, tear gas, and hundreds of arrests.

"Initially, the police in both Oakland and England were caught off guard, and they themselves said that they couldn't control the situation," said Rachel Jackson, an activist with Oakland's New Year's Movement for Justice. "In January of 2009, the [Oakland] police and the city and state governments were quick to bring out all of their crowd control equipment and machinery."

Months later, when Johannes Mehserle, the officer who shot Grant, went to trial for murder, documents obtained by Al Jazeera show that the Oakland Police Department [OPD] prepared itself for intense unrest, calling in the Federal Bureau of Investigation (FBI), the FBI's Joint Terrorism Task Force, the Department of Homeland Security (Secret Service agents and the Northern California Regional Intelligence Center), the Drug Enforcement Agency (DEA), the California Department of Justice, and at least 16 other local police agencies, in what it dubbed "Operation Verdict".

OPD Assistant Chief Howard Jordan told Al Jazeera that each of those state and federal agencies have a "regular" relationship with the OPD "for the purposes of assisting day-to-day crime fighting", and declined to respond to any questions regarding the unrest.

Police in Oakland stocked an arsenal of "less than lethal" weapons and munitions. According to official documents, OPD prepared itself with munitions "estimated to last approximately seven days of full scale deployment".

"The police did a major public relations campaign to scare people out of coming on to the streets at the time of the verdict," said Jackson.

"It was as if, from the police statements and the mayor's office statement, that there was going to be a bomb dropped and people had to evacuate," said Walter Riley, a long-time civil rights lawyer in Oakland.

'Operation Verdict'

On July 8, 2010, a jury that did not include a single black person convicted Mehserle of the lowest possible charge, involuntary manslaughter.

Demonstrators took over the city's central intersection. FBI, DEA and OPD helicopters buzzed overhead, 46 undercover officers from the OPD, California Department of Justice and DEA infiltrated the crowd, and secret service agents in OPD uniforms recorded the events on video, according to official documents and videos.

"There were a lot of young people who didn't necessarily know Oscar Grant, but saw him as themselves," said Riley. "There was a lot of identification with senseless brutality against people of colour."

Near the start of unrest on July 8, 2010, an image of Riley being arrested in his suit and tie, with a bright green cap identifying him as a legal observer, was broadcast on local news. Riley, in his 60s, speaking recently, told Al Jazeera that he was choked while being arrested.

"Their reason for arrest was resisting arrest and failure to disperse from the scene of a riot," he said, but the District Attorney dropped all charges. A police email two days after the arrest identified Riley as a "Community Leader".

Riley represented another arrestee in court, and said the police report on his client identified him "as 'a young black man wearing dreads and looking angry'", and used that description as pretense for making the arrest.

By the end of the night, 84 people had been arrested, fires smouldered in rubbish bins and cleanup crews cleared shattered storefront windows.

'Operation Sentence'

Four months later, a Los Angeles judge sentenced Mehserle to two years in jail, which would be cut in half for good behaviour. Hundreds of demonstrators again took to the streets, and police came prepared as they had in July, this time calling the event "Operation Sentence".

Police documents show Operation Sentence involved the FBI, DEA, the California Department of Justice and 569 officers from at least 20 other local police agencies - clearly outnumbering protesters.

Security forces on November 5 surrounded a large group of people as they were marching away from downtown, allowed members of the media to exit the scene, and made 152 arrests.

"[Protesters] were corralled by hundreds of militarised police. They were given no opportunity to disperse," Michael Flynn, the President of the San Francisco chapter of the National Lawyers' Guild (NLG), told Al Jazeera.

The OPD now faces a class action lawsuit filed by the NLG - a national association of progressive lawyers, legal workers and law students - which claims that police actions on November 5 were "violations of constitutional and statutory rights".

The lawsuit says that the OPD and cooperating agencies violate the OPD's own crowd control policy, and that the mass arrests amounted to violations of the first, fourth and fourteenth amendments to the US Constitution, false arrest, false imprisonment, negligence, and three California state laws.

It also says the arrest procedure included "an hour and a half seizure and detention on the street", after which arrestees were loaded onto buses and denied restroom access. "Many of the class members [were] forced to urinate on the floor of the bus where they were sitting or standing."

Citing the lawsuit, police officials declined interview requests.

'Militarisation' of police

Jackson, who was arrested in Operation Sentence, says that if the same unrest in either Oakland or the UK took place in Libya, they would be called "protests" instead of a "riot", a term that "tends to be paired with 'senseless violence' and 'pure criminality'".

She says that the difference allows police to take advantage of their perceived power to create a degenerative crackdown on dissent.

Activists say the use of 'riot' removes value from the political nature of events [Jesse Strauss/Al Jazeera]

"Police have increasingly militarised the United States over the past decade," says Michael Flynn. "They now see themselves more as soldiers in the battlefield, and I think we saw that in November."

The OPD consumes 40 per cent of Oakland's budget, and the city of about 400,000 is expected to spend $58m more than it will receive in revenues this year. Furthermore, the OPD is expected to spend more than $13m in one year of overtime pay alone, according to police documents.

The police department is now prepared for future battle. It has 90 new cases of .40 calibre ammunition, 20 cases of shotgun shells, 1,750 tear gas canisters and 3,000 new bean bag shotgun discharges. The OPD's crowd control policy says that these type of bean bags "shall not be used for crowd management, crowd control or crowd dispersal during demonstrations".

It also has at least four new high-definition video cameras and a Long Range Acoustic Device (LRAD), which can be used to "make announcements to crowds" or "produce high pitch noise" strong enough to damage eardrums or potentially cause fatal aneurisms. The LRAD has reportedly been used against both Somali pirates and Iraqi insurgents.

Across the pond

In the UK, the response to intense unrest that rocked numerous cities earlier this month is still in the works, but it is clear that some Oakland and US-style policies are being imported.

Among them, David Cameron, the country's prime minister, has accused the police of acting too slow and without enough force. He has also defended tough sentencing policies and said that his government wants to "send a very clear message that it's wrong and won't be tolerated".

London's acting police commissioner said that the government, which has already charged more than 1,000 people with riot-related crimes, was aiming for 3,000 convictions, and that the investigation was "far from over".

To prepare for future riot control measures, the British government has commissioned William Bratton, a former police chief of New York, Los Angeles and Boston, as an advisor. Members of the British police have said bringing Bratton on is a bad idea, and contended that the only thing needed by police in order to handle situations like this month's unrest is greater levels of funding.

There has been talk of bringing in the British army to assist police in the case of further unrest that causes property damage.

In the same subway system where Oscar Grant was killed, another man was shot dead by officers in July. In response, community members protested multiple times, and, in a first for the US, a public agency (the subway system) shut down mobile phone access in its stations in a bid to prevent protesters from organising demonstrations.

Meanwhile, the officer who killed Duggan has not been named, let alone prosecuted.

Although it is unclear to what extent, Britain's tactics to control public disorder will be influenced by US policing schemes, and activists hope that the policing in the UK won't violate civil liberties, as has been alleged in Oakland.

"British officials will learn a few new crowd control tricks from the American colleagues," says Rachel Jackson. "But the US curriculum relies on sowing division and distrust in communities, denying civil liberties, and the increasing militarisation of society, especially in poor and increasingly violent neighbourhoods."